Messages in this thread Patch in this message | | | From | Eduardo Valentin <> | Subject | [PATCH 14/15] thermal: sysfs: serialize access to instances | Date | Mon, 30 May 2016 23:31:35 -0700 |
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Because instances are the result of a matching between cdev and tz, we need to lock both in order to access the instance reliably.
This patch locks both tz and cdev in user facing sysfs handlers when accessing thermal zone instance.
Cc: Zhang Rui <rui.zhang@intel.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eduardo Valentin <edubezval@gmail.com> --- drivers/thermal/thermal_sysfs.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index ab78e08..31314be 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -781,14 +781,20 @@ thermal_cooling_device_trip_point_show(struct device *dev, struct device_attribute *attr, char *buf) { struct thermal_instance *instance; + int trip; instance = container_of(attr, struct thermal_instance, attr); + mutex_lock(&instance->tz->lock); + mutex_lock(&instance->cdev->lock); + trip = instance->trip; + mutex_unlock(&instance->cdev->lock); + mutex_unlock(&instance->tz->lock); if (instance->trip == THERMAL_TRIPS_NONE) return sprintf(buf, "-1\n"); else - return sprintf(buf, "%d\n", instance->trip); + return sprintf(buf, "%d\n", trip); } ssize_t @@ -796,10 +802,16 @@ thermal_cooling_device_weight_show(struct device *dev, struct device_attribute *attr, char *buf) { struct thermal_instance *instance; + int weight; instance = container_of(attr, struct thermal_instance, weight_attr); + mutex_lock(&instance->tz->lock); + mutex_lock(&instance->cdev->lock); + weight = instance->weight; + mutex_unlock(&instance->cdev->lock); + mutex_unlock(&instance->tz->lock); - return sprintf(buf, "%d\n", instance->weight); + return sprintf(buf, "%d\n", weight); } ssize_t @@ -815,7 +827,11 @@ thermal_cooling_device_weight_store(struct device *dev, return ret; instance = container_of(attr, struct thermal_instance, weight_attr); + mutex_lock(&instance->tz->lock); + mutex_lock(&instance->cdev->lock); instance->weight = weight; + mutex_unlock(&instance->cdev->lock); + mutex_unlock(&instance->tz->lock); return count; } -- 2.1.4
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